USB HUB Problem: "disabled by hub (EMI?), re-enabling"

Simo Azz

Other Parts Discussed in Thread: DM3730, ASH

Hi,

We are working on a project using a board which mounts a DM3730 processor which runs a Linux distribution and we are experiencing problems in runtime.

Our board is interfaced with an our custom expansion board. On our board are mounted other ICs as one USB HUB, 3 FTDI232 usb/rs232 converter, and a

micro-controller.

The firsts versions of the project was using a OMAP 3530 with an ängstrom distribution and kernel 2.6.34, and everything has always worked fine without problems.

Now, we are working with a DM3730 with a Linux distribution using kernel 3.18.18. The expansion board is always the same, but sometimes the USB hub get
totally disconnected reporting the error

"disabled by hub (EMI?), re-enabling ..."

which, in Linux kernel, is handled in the file:

drivers/usb/core/hub.c

This error was already handled in kernel 2.6.34.

The problem is that the USB hub is not re-enabled again. It remains unconnected (as it should powered off) and we are unable to reset it neither with an external micro-controller. No way to re-enable it.

If we reboot our board (and so the Gumstix board as well), everything turns to work again. We need to solve it because without HUB our project cannot work properly..

Thank you in advance.
Simon

over 9 years ago

0 Titusrathinaraj Stalin over 9 years ago

TI__Guru** 116100 points

Can you please try to insert the USB driver as module ?
If not workout in first time, try to remove the module & re-insert the module driver again...

0 Simo Azz over 9 years ago in reply to Titusrathinaraj Stalin

Prodigy 185 points

Hi Titus,

Thank you for your reply.

I though to compile the relates modules as external and give it a try, but I don't think this is a solution.

After looking for news online, I knew that it could be from DPLL5 register issue as specified here:

www.ti.com/lit/er/sprz319f/sprz319f.pdf

in note Advisory 2.1 at page 110.

Perhaps this could be really the root of these problems ?

Regards.

Simon

0 Steve Kipisz over 9 years ago in reply to Simo Azz

TI__Genius 15510 points

I used to see that error. After changing the M/N for DPLL5 as per the advisory, the error went away.

Steve K.

0 Simo Azz over 9 years ago in reply to Steve Kipisz

Prodigy 185 points

Hi Steve,

Thank you for this important information. But it's still not clear to me what part of the kernel code have to modify in order to solve this issue.

I suppose is in

arch/arm/mach-omap2/

in clock related files (clk3xxx.h and clk3xxx.c) but I am not sure.

Could you suggest me how or which file I have to modify?

Thank you in advance.

Regards,

Simon

0 Titusrathinaraj Stalin over 9 years ago in reply to Steve Kipisz

TI__Guru** 116100 points

Please refer to the following links.
e2e.ti.com/.../247010
git.ti.com/.../8f1fc028be8567c57ed7d40b1800ece37128b9ac
github.com/.../0001-Fix-sprz319-erratum-2.1.patch

0 Simo Azz over 9 years ago in reply to Titusrathinaraj Stalin

Prodigy 185 points

Hi Titus,

This patch is for kernel 3.0, while I am working with a kernel 3.18.18.
I tried to apply the changes manually but the compile process fails.

If there is no other solution I will retry to adapt the patch to the kernel 3.18.18.

Simon

0 Simo Azz over 9 years ago in reply to Titusrathinaraj Stalin

Prodigy 185 points

Hi Titus,

The patch for the kernel 3.0 cannot be applied to the kernel 3.18.18 because the code is not compatible: arguments variables for many functions are different and these function

I would like to know from Steve, if possible, if he applied the modification to a kernel 3.18.18 or how he did the modification, please.

Thank you.

Regards,

Simon

0 Steve Kipisz over 9 years ago in reply to Simo Azz

TI__Genius 15510 points

I did not apply it.

Steve K.

0 TK421 over 9 years ago in reply to Simo Azz

Prodigy 10 points

Simon,

Any update on whether you were successful with patching your 3.18.18 kernel? We have a similar sounding situation with a custom Yocto distro running a 3.18.18-custom kernel.

Tim

0 Simo Azz over 9 years ago in reply to TK421

Prodigy 185 points

Hello Tim,

Yes, I solved the issue. At the time, I opened an issue here:

http://gumstix.8.x6.nabble.com/USB-HUB-Problem-quot-disabled-by-hub-EMI-re-enabling-quot-td4970638.html

Following the suggestions from Ash Charles, I took a look the modifications from GH. I finally donwloaded the entire kernel, here:

https://github.com/gumstix/linux/tree/9084a45df0d8130542ec18df1f255670c93a0f28

I recompiled and the issue seems solved.

: )

Give it a try !

Regards,

Simon

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USB HUB Problem: "disabled by hub (EMI?), re-enabling"